Insulation for electric conductors



(No Model.)

C. T. SNEDEKOR.

INSULATION POR ELECTRIC GONDUGTOIIS. 110.408,901. Patented Aug. 13, 1889.

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MIM X TERS. Phunrumngrapner. wnhinglcn, D. C.

UNITED STATES PATENT OFFICE.

CHARLES T. SNEDEKO'R, OIF ST. LOUIS, MISSOURI.

INSU LATION FOR ELECTRIC CONDUCTORS.

SPECIFICATION forming part of Letters Patent No. 408,901, dated August 13, 1889.

Application filed June 21, 1889. Serial No. 315,114. (No model.)

To @ZZ whom, t may concern:

Be it known that I, CHARLEs T. SNEDEKOE, a citizen of the United States, residing at St. Louis, in the State of Missouri,have invented certain new and useful Improvements in Insulation for Electric Conductors; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appcrtains to make and use the same.

My invention relates to the insulation of electric conductors and other metallic arti* cles and substances; and it consists in a fireproof coating or covering', the particular construction of which is set forth in the following description and claims.

Many experiments have been made looking to the attainment of the results accomplished by my constructiombut, so far as I am aware, with only partial success, many of the conductors, when insulated in the way proposed, being' incapable of bending without cracking or breaking the coating and thus destroying the insulation.

By my improvement I am able to produce an insulated cable-wire or other similar conductor which has all the flexibility of the original conductor, and which at the same time is able to resist the act-ion of fire.

In order that others may understand the nature of my said invention and the man` ner of making and using the same, I have illustrated my preferred form of cable in the accompanying drawing, in which is shown an enlarged view of a metallic conductor provided with layers of insulating material, and I will now proceed to describe the same.

The wire, cable, or other conductor to be insulated is first covered with a coating of liquid shellac, and before this is dry a coating or covering is applied to the conductor, consisting of some fibrous material-such as cotton, jute, silk, or other similar substancewhich has been saturatedin a strong solution of alum. This coating is then allowed to become perfectly dry, after which a liquid glue of any preferred kind is applied, upon which, when hardened, I spread a thick coat of heavy varnish. IVhile this varnish is yet damp a dust is applied,consisting, preferably, of' about four parts of powdered or ground glass, one

part powdered alum, and one part powdered asbestus. The conductor is then again covered with a fibrous coating which has been fir'st thoroughly saturated with a composition or paste consisting of linseed-oil, litharge, White lead, ground asbestus, and alum. I again cover this With fibrous material which has first been saturated with a solution of alum and allowed to dry. To this dry fibrous Y coating I next apply a solution of any of t-he varnish gums dissolved in linseed-oil, and before this coating hardens there is pressed into it a thin coat of asbestus fiber. VWhen this is perfectly dry and hard, the whole is thoroughly coated with varnish.

While I prefer to use all of the ingredients mentioned in the manner set forth, some of the ingredients and parts mentioned may be omitted and yet good results attained. For instance, the coating of glue may be omitted and the powdered glass may be omitted from the dust coating, and the litharge or white lead may be left out of the composition or paste without any great detriment to the insulation.

Vhat I claim, and desire to secure by Letters Patent, is-

l. An insulatingcovering for electric conductors and other metallic substances, consisting of a coating of alum-saturated fiber secured to the article to be insulated by shellac, a coat of varnish upon said fiber, a powd ered non-iniiamm able coating upon said varnish, a fibrous coating filled with a paste compound of a mineral substance or substances, a coating of dry alum-saturated fibrous material, an asbestus covering, and an outer coating of varnish, substantially as described.

2. An insulating-covering for electric conductors and other metallic substances, consisting of a coating of alum-saturated fibrous material secured to the article to be insulated by shellac, a coat of varnish upon said fibrous material, a powdered non-iniiammable coating upon said varnish, a fibrous coating filled with a paste compound of a mineral substance or substances, a coating of dry alum-saturated fibrous material, a coating of gum and oil, an asbestus covering, and an outer coating of varnish, substantially as described.

3. An insulating-covering for electric conductors and other metallic substances, con- IOC sisting of a coating` of alum-saturated iibrous material secured to the article to be insulated by s'hellac or its equivalent, a coating of glue, a coat of Varnish upon the glue When hardened, a coating,` of non-inflammable substance upon said Varnisl1,a fibrous coating,` lled with a paste compound of a mineral substance or substances, a coating` of dry aluLn-satinated fibrous material, a coating,l of gum and oil, au. asbestus covering, and an outer coating` of varnish, substantially as described.

l. An insulating-covering for electric conductors and other metallic substances, con- Sistine` of a coating,` ol' alum-saturated iibrous material secured to the article to be insulated by shellac or its equivalent, a coating of glue, a coat of Varnish upon the `glue When hardened, a non-inflammable coating consistingI of a composition of powdered or ground glass, powdered alum and ground asbestus, a fibrous coating' i'llled with apaste compound of a inin* eral substance or substances,a coating of dry alum-saturated iibrous material, a coating ol' `quin and oil, an asbcstus covcri ug, and an outer coating' of varnish, substantially as described.

5. An insulating-covcring for electric conductors and other lmetallic substances, consistingl ol' a coating ol aluin-satu rated fibrous material secured tothe article to be insulated by shellac or its equivalent, a coating of glue, a coat ol Varnish upon the glue, a coating olj non-inflammable substance or substances, a fibrous coating` filled with a paste compound composed of litharge, ground asbestus, alum, and oil, a coating olf dry alu1n-saturated :librous niaterial, a coating ol gum and oil, an asbestus covering, and an outer coating of varnis`l1,substantially as descriliied.

ln testimony Whereol` I allix my signature in presence of two witnesses.

CHARLES '.l. SNEDEKOR. Witnesses:

L. B. XVHITAKER, Rorxr. ll. PAYNE. 

